Method and apparatus for R-F ablation

Abstract

An ablation catheter and a method of performing cardiac ablation. The catheter is provided with a hollow, helical electrode, which is screwed into cardiac tissue at a desired ablation site and connected to a source of R-F electrical energy to ablate the tissue adjacent the electrode. Prior to ablation, a conductive fluid may be injected through the hollow needle, both to provide for cooling of the tissue adjacent the needle and to increase the conductivity of the tissue in the area of the electrode.

In conjunction with the above specification, we claim: 
     
       1. A catheter system, comprising a catheter and a fluid reservoir, wherein said catheter comprises: a catheter body proximal end, a distal end, an internal longitudinal lumen;   a hollow helical needle mounted to the distal end of said catheter body, in fluid communication with said longitudinal lumen; and   a fluid coupling mounted to the proximal end of the catheter body, in fluid communication with said longitudinal lumen; and   wherein said fluid reservoir is coupled to said fluid coupling whereby fluid in said reservoir can be delivered through said hollow helical needle.   
     
     
       2. A system according to claim 1 further comprising means for regulating flow from said reservoir to said hollow helical needle. 
     
     
       3. A system according to claim 1 or claim 2 wherein said reservoir contains a saline solution. 
     
     
       4. A system according to claim 3 wherein said catheter body further comprises an electrical conductor, coupled to said hollow helical needle. 
     
     
       5. A system according to claim 1 or claim 2 wherein said reservoir contains a conductive fluid. 
     
     
       6. A system according to claim 5 wherein said catheter body further comprises an electrical conductor, coupled to said hollow helical needle and extending proximally therefrom in said catheter body. 
     
     
       7. A system according to claim 1 or claim 2 wherein said catheter body comprises a torque transfer member, coupled to said hollow helical needle. 
     
     
       8. A system according to claim 7 wherein said torque transfer member comprises a torque cable, coupled to said hollow helical needle and extending proximally therefrom in said catheter body. 
     
     
       9. A system according to claim 7 wherein said torque transfer member is coupled to the proximal end of the catheter body. 
     
     
       10. A system according to claim 7 wherein said torque transfer member is fabricated of a conductive material. 
     
     
       11. A system according to claim 7 wherein said reservoir contains a conductive solution. 
     
     
       12. A system according to claim 11 wherein said catheter body further comprises an electrical conductor coupled to said hollow helical needle and extending proximally therefrom in said catheter body. 
     
     
       13. A system according to claim 7 wherein said reservoir contains a saline solution.